On Tue, Sep 4, 2012 at 9:29 AM, John Hearns <hearnsj at googlemail.com> wrote:
> On 4 September 2012 14:16, Robert G. Brown <rgb at phy.duke.edu> wrote:
>>>> On a more serious note, one wonders why nobody has tried helium instead.
>> No, silly, not liquid helium, helium gas. The reason they fill windows
>> with argon is that it has around 2/3 the thermal conductivity of air,
>> and hence is a better insulator. This, in turn, is because it is more
>> massive -- conductivity is tightly tied to mass and hence the speed of
>> the molecules when they have kT sorts of energies.
>>>> Helium, OTOH, has six times the thermal conductivity of air, and is
>> relatively inexpensive.
>> Helium was also used in Formula 1 wheel guns.
> Wheel guns are the comoressed air tools which the mechanics use in a
> pit stop to undo
> and refasten the wheel nuts - the faster you can do this the faster
> the car gets back out on the track.
> Lower inertia means the guns were spinning faster.
>>http://jalopnik.com/5863687/a-farewell-to-helium+powered-wheel-guns>> As this article points out, helium is a finite resource. If all teams
> were using it, there would
> be no advantage to any one team and it would be wasteful of a resource.
> If I'm nto wrong the US Government holds the biggest stock of helium,
> somewhere in a salt some in Texas.
> And not more of it is being produced in the world.
I believe the Congress mandated that the reserve be sold. The sudden,
large increase in supply has suppressed prices so that much of it is
literally going up in party balloons. Once it is gone...
Scott